Nanostructured ionic segmented copolymers as alternative membrane for fuel cell and aqueous redox flow batteries

The membrane is a critical component in redox flow batteries (RFBs) significantly influencing their performance, especially in terms of columbic efficiency and capacity retention. The membrane provides ion conduction pathways to make a conductive circuit and enable to specific ions to pass through, avoiding the crossover between the catholyte and anolyte. The most commonly used membranes in this system are perfluorinated membranes, well known as Nafion & Aquivion. Their perfluorinated backbones, functionnalized with sulfonic acid groups, allow them to self-organize into percolated hydrophobic/hydrophilic domains. We propose alternative ether-free polymer membranes. To fully leverage the advantages of these polymers, our approach has been to develop segmented polymers with well defined hydrophilic and hydrophobic segments, allowing us to optimize the specific properties of each segment.